Effects of Parking Provision on Automobile Use in Cities: Inferring Causality

Download PDF Document (0.2MB)
November 13, 2015
By: Chris McCahill, Norman Garrick, Carol Atkinson-Palombo, Adam Polinski

Automobile use has been on the rise in cities for nearly a century and so has the supply of parking. Because driving often seems unavoidable, policymakers, developers and the public push endlessly for more parking to meet demand. That push, however, might only be making matters worse.


new study on the subject, co-written by Chris McCahill from our own State Smart Transportation Initiative, strongly suggests that abundant parking in cities causes people to drive more, shedding important light on the question of cause and effect. 


Admittedly, this isn’t a new idea. For the past several decades, a handful of researchers have studied the purveyance of free parking in the U.S., its hidden costs, and its effects on travel behavior. By examining individual streets, buildings and neighborhoods, study after study has shown that people respond to the price and availability of parking by adjusting their driving habits. That’s especially true in cities, where there are usually more options for getting around.


Yet as cities grow, more often than not, so do their parking supplies. City records that we uncovered in an earlier study show policymakers demanding more parking year after year, even as they worry about the impacts it could have on the built environment and car use. And so we’ve been left to wonder whether cities are simply adapting to the automobile in order to grow, or perpetuating urban automobile use. Read more in the full report above.